Prior to the present invention, as shown by Uzgiris et al., Two-Dimensional Crystallization Technique for Imaging Macromolecules, With Application to Antigen-Antibody-Complement Complexes, Nature, Vol. 31, No. 5896, pp. 134-136, January 1983 and Kornberg, U.S. Pat. No. 4,489,133, a technique for effecting two-dimensional crystallization of macromolecules as an ordered monolayer were available. Two-dimensional ordering of organic polar solvent soluble organic macromolecules, such as poly(amino acids), was achieved by Kornberg by placing a supported lipid monolayer in a polar solution of the organic macromolecules. The organic macromolecules were allowed to incubate for a sufficient period of time to effect their two-dimensional crystallization.
Although valuable results have been achieved by the method of U.S. Pat. No. 4,489,133, for particular macromolecules, such as antibody IgG, effective results have not been found for growing a wide variety of other macromolecules as ordered monolayers. Experience has shown that the lipid monolayer of Kornberg has a tendency to separate too quickly from its supporting substrate before a sufficient incubation period has been achieved to allow sufficient nucleation. In addition, even though limited success has been achieved with growing ordered monolayers of IgG, the linear crystalline patterns of IgG macromolecules were often irregularly spaced as observed under an electron microscope due to insufficient lipid substrate support. It would be desirable, therefore, to provide a supported lipid substrate capable of allowing sufficient incubation time while in an aqueous medium, to effect the nucleation of a wide variety of macromolecular ordered monolayers.
The present invention is based on the discovery that a lipid polylayer having at least two hydrophilic regions and at least one lipophilic region and supported on one of its hydrophilic regions by a hydrophilic substrate, can provide significantly improved two-dimensional crystallization of a wide variety of macromolecules, as compared to results achieved with a lipid monolayer.